Ortho-carboxyamidothioglycolic acid



Patented May 7, 1929. 1

UNITED STATES PATENT OFFICE.

NORBER'I' STEIGER, F FRANKFORT-ON-THE-M-Am, AND ERWIN HOFFA AND HAN-$1 HEYNA, 0F HOCHST-ON-THE-MAIN, GERMANY, ASSIGNORS TO GRASSELLI DYE- STUFF CORPORATION, 01 NEW YORK, N. Y., A CORPORATION OF DELAWARE.

ORTEO-GARIBOXYAIMIDOTHIOGLYCOLIC ACID.

No Drawing. Application filed March 30, 1928, Serial No. 266,111, and in Germany April 12, 1927.

Our copending application Serial N o. This can be ascertained in the following man- 50 266,110, filed on the same date, relates to new ner: A test of the reduction massis taken ortho-carboxyamidoarylthioglyeolic-ac1ds of from time to time and is diluted with water,

th general f l the organic residue is filtered off, the filtrate is /OONH2 made alkaline and boiled. Only tracesof aryl 2 (2), h 2311151101113, should be ascertainable in these 55 s s. v

wherein alyllmeflns a Substituted aryl When the reduction is finishe th a 3 P3 9 maklng m Whlch or chlorobenzene respectively i3 disilz l sff d fi 10 Q P ej the correspondmg and the residue is diluted With water and cyanarylsulfochlorides under such cond1- filt d fl' The mercapto compound h 60 whereby orthowarboxyam1da 1'yhner formedof the probable constitution of an captanes are formed, and c 1 g 1 8tll0X Y--l-C2LIlJOXyQJIIldObCIIZGDQ-3--II1QI'C3P- products thus Obtalne i111 fillkahne Solu' tane can directly be used for further technical 15 tlon Wlfll monpchlorpacetlc-acldpurposes. It is'without being purified mixed Qur present 1nvent10n r certain with about 300 parts of water and dissolved bodiments of the above 111 9 fi of by addition of about 40 parts of a caustic c p u s of which Q followlng 18 all 111113 soda solution of 33 B. and 10 parts of monotrative example in which the parts are by chloroacet-ic-acid are added. The condensa- 20 Welght and all temperatures are 111 Centlgrade tion takes place at ordinary temperatures and degrees: is finished in a relatively short time. For 70 Emample: prgcipitai ting; 1the frilale acid the mass is acidie re era wit ad i' 35 P F of 1"ethyoxy4cyanbenzene'3'Su1* voluriie of a coinmon Salt SZ lZ lilOZ the same fochlorlde of the formula: The l-ethoxy 4- carboxyamidobenzene-i- ON thioglycolic acid of the formula:

Canto 02C] CONH:

' CgHaO 3 obtainable'for instance according to the proc- SCHZCOOH ess mentioned in the copending application by Starting from the corresponding thus separates as awhite crystalline powder. phenetidine sulfonic acid are dissolved in It is soluble in hot watenand 1n the usual about 100 parts of benzene or-chlorobenzene, orgamc osolventsi meltlng P State at and at ordinary temperature slowly 20 parts 208*210 of zinc-dust are added, the temperature in- In Same manner.the

creasing to about 60. After stirring for bQXXam1dbenZene73"thloglycollc'acld can be about an hour at this temperature the mass is Obtalned',

-c0oled down and at about 100 parts of hy- We clam 4 drochloric-acid (d=1,19) and again 20 parts AS new comp?llnds y y of zinc dust are slowly added. The mass is amldobenzeneg"thloglycohc acIds 0f the 90 stirred at ordinary temperature for some formula: hours. The reaction is finished when a test 0 1; shows that the well known mercaptane reaction (namely a yellow coloration with lead alk 0 E acetate) does not increase any more. Care should be taken, that during the whole procbeing when dry white crystalline powders,

ess of reduction practically no nitrogen of the soluble in hot Water and the usual organic cyanie-group is split off in form of ammonia. solvents.

' 2. vAs a new compound the l-ethoxy--carboxyamidobenzene-3-thioglyc.olic acid. of the being when dry 3. white crystalline powder formula.

soluble in hot water and in the usuah organic solvents, and melting in a. pure state at 10 2O821O.

In testimony where0f,- we aflix our signatures.

NORBERT STEIGER. ERWIN HOFFA. HANS HEYNA. 

